OBJECTIVES: Lymphocyte response to mitogens can be either suppressed or augmented by antibody directed towards the stimulating mitogen. The objective of these studies is to determine the mechanism of anti-mitogen antibody regulation of lymphocyte response, and to relate these findings to the interaction of lymphocytes, antibody and tumor antigens. GOALS: 1) Measure the temporal requirements for lymphocyte suppression by antibody. 2) Investigate the ability of different classes of immunoglobulin to induce the central suppressive event. 3) Evaluate the ability of divalent and monovalent antibody fragments to suppress phytolectin induced proliferation. 4) Determine the fate of cell bound phytolectins and antibody.